Accuracy test for in-vitro micro-computed tomography

Abstract

The present work aims to describe and discuss the application of an accuracy test for in-vitro micro-computed tomography (microCT). Accuracy of morphometric measures is required to the analysis of bone microstructure and the mechanical characterization of the tissue. The accuracy test was introduced in a program of quality control designed for trabecular bone morphometry. It was applied using a physical calibration phantom that reproduced the three-dimensional structure of the typically investigated object, i.e. trabecular bone structure. The phantom was used to test the quality of accuracy measurements. The absolute error was chosen as the quality control parameter in accuracy test. The Shewhart control chart was introduced to monitor the quality control parameter. Baseline value was calculated as reference value for the control chart during acceptance/status test. An out of control condition was defined as the monthly measure that was out of the tolerance limits determined by the adopted chart. A maintenance service has been suggested upon the occurrence of this condition. During the monitoring period of 15-months no out of control conditions in accuracy test were recorded, as confirmed by the statistical C and Kruskal Wallis tests. Thus, by application of the accuracy test, the performance of the microCT system was found to be in control.